Improvement in pressure safety attachments for house boilers



E. STEELE. PRESSURE SAFETY ATTACHMENT FOR HOUSE BOILERS.

No. 193,049. Patented. Ju1y 1 0,1877.

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UNITED STATEa eEoEsE STEELE, or NEW YORK, N. Y.

IMPROVEMENT IN PRESSURE SAFETY ATTACHMENTS FOR HOUSE BOILERS.

Specification forming part of Letters Patent N0- l93,049, dated July 10, 1877 application filed December 27, 1876.

To all whom it may concern Beit known that I, GEORGE STEELE, of the city, county, and State of New York, have invented an Improved Pressure Safety Attachmentv for House-Boilers; and I hereby declare that the following is a full, clear, and exact description of the same.

My invention is specially applicable to boilers used for domestic purposes, usually placed in kitchens and connected with kitch enranges, and which supply hot water to baths, laundries, and lavatories. In boilers of this class, as ordinarily arranged and constructed, when the water is not drawn off for some time, or is drawn ofi" only in small quantities, while the fires in the ranges with which such boilers are connected are vigorously main tained, steam accumulates in the boilers in such quantities as to force the water out of the boilers against the pressure of the water from the water-mains which supply them. When this occurs, and a faucet is opened in a pipe to obtain hot water from any such boiler, the steam rushes out with great force and rapidity, while the water rushes in much more slowly. The violence of the efflux of steam frightens the servant, who, without reflection, suddenly closes the faucet. A frequent result is that the inflowing cold water condenses the steam remaining in the boiler so suddenly that the water cannot at once fill the vacuum so produced, and the external pressure of the air collapses the boiler.

1 To prevent this accident, and also to prevent damage to the water-back in the range with which such boiler is connected, resulting from obstruction of the pipe through which water circulates from the boiler to the said water-back, and to supply a means whereby the undue accumulation of steam in either the boiler or the water-back may be constantly and automatically prevented, are the objects of my invention.

The invention consists in independent and separate pipes,separately and independently connected both with thewaterback in the ran go by which thewater is heated and the boiler, and with the boiler and the water-main from which the boiler is supplied, said pipes being also connected with each other, and extending from said water-back and boiler to said main, and

having a common communication with said main by a connection separate and independent from that of the pipe through which water from said water-main is supplied to the said boiler, said pipes having check-valves, which prevent the passage of water through them into said boiler and water-back from the said water-main, but which allow the passage of steam through one or both of said pipes to said watermain whenever the pressure in the said pipes is enough greater onthe under sides of said check-Valves, respectively, facing toward the said boiler and water-back, than on the upper sides facing toward the said. water-main, to overcome the weight of, and to raise, said check-valves from their seats.

Figure 1 in the accompanying drawing is a plan view of a water-back, boiler, supply-pipe leading from a water-mainto the boiler, and my pressure safety attachment thereto attached, with the parts arranged in proper relation for use. Fig. 2 is an elevation of the same, with sectional view of one of the checkvalve boxes, showing the check-valve within;

and Fig. 3, a detail of a portion of the apparatus.

B represents the boiler, and M the watermain. P is the pipe which supplies water from the said main to the said boiler in the usual manner, entering the boiler at the top and descending nearly to, and delivering'the water nearly at, the bottom of the boiler. To this pipe is united the cold-water service-pipe p, which supplies cold water to various parts of the building in which the apparatus is placed.

The water passes from the boiler B to the water-back W, through the pipe P', Fig.2, and when the saidwater-back W is heated water circulates upward through the pipe P to the said boiler, and downward through the pipe Pm Connected withboth the top of the waterback W and the top of the boiler B is the pipe P, which leads back to and is connected with the pipe P, which leads back to and opens into the water-main M, and which is also connected with the top of the boiler B.

In the pipe 1? is placed the check-valve box 0, and in the pipe P is placed the checkvalve box (3. The check-valve box 0 contains the valve V, Fig. 3-, and the check-valve box 0 contains the valve V, the valve V being located in the pipe P, be ween the boiler B and the water-main M, and the valve V being placed in the pipe P, between the boiler B and the water-back W.

The said check-valves are arranged to close when the pressure is equal on both sides of the same, but when the pressure is greater on the side of the valve V, which faces away from the water-main, than on the side of the same which faces toward said main, the said valve will open and establish a free passage from the boiler to the main M, through the pipe P. This difference of pressure occurs whenever there is sufficient accumulation of steam to force down the level of the water in the boiler to a moderate distance below the top of said boiler, because the water-column in that part of the pipe P which lies between the main M and the check-valveVacts against the pressure of the water in the main M, while the pressure of the water-column in that part of the supply-pipe P which descends nearly to the bottom of the boiler inside of the same, and which pressure, when the boiler is full of water, is counterbalanced by the pressure of the water in the boiler, has a siphon action when the water in the boiler is so depressed which counterbalances in great measure the I backward pressure of the water in that part of the said pipe P lying between the watermain and the boiler, and thereby assists the pressure in the said main, and this combined pressure is transmitted to the interior of said boiler. The accumulated steam, then raising the valve V, escapes, and passing into that part of the pipe P -lying between the said valve V and the main M, is condensed, and the pressure in the boiler B is thereby relieved till the said check-valve again closes upon the equalization of the pressure in the.

said boiler and pipe P, by the entrance of water into said boiler.

It occasionally happens that the pipe P becomes wholly or partially stopped by sedi-- ment or other obstruction.

tion between the boiler and water-back is wholly impeded by the obstruction of the pipe P, the water remaining in the water-back may ultimately all be converted into steam, which steam will depress the water in the boiler below the upper open end of the pipe P. The steam in the water-back under such conditions will be superheated. The waterback will then be damaged by overheating.

Moreover, if under such conditions the obstruction in the pipe'P suddenly yields, and allows even a small quantity of water to pass from the boiler to the water-back, the total destruction by explosion or fracture of the said water-back may and sometimes does occur.

To prevent these consequences I connect the top of the water-back W with the top of the boiler B by the pipe P, which is also connected with the pipe P, placing the checkvalve V between the said boiler and the said water-back, which prevents any passage of steam or water from the boiler through the pipe P to the said water-back, but which, when on account of the obstruction of the pipe P, steam is generated in the said water-back under sufficient pressure to raise the check-valve V, allows the said steam to pass to the boiler, and from thence out through the check-valve V and the pipe P to. the 7 main M.

The accumulation of steam to such an extent as to endanger either the water-back or the boiler is thus entirely prevented.

The pipe P, with the check-valve V, may, however, be used without the pipe P, it havin g a separate and independent action, as hereinbefore described. In such case the pipe P will terminate at its connection with the boiler.

Iclaim- 1. The pipe P, provided with the checkvalve V, placed between the boiler B and the water-main M, and. separately and independently connected with said boiler and watermain, substantially as and for the purpose herein specified.

2. The pipe P, connecting the water-back W with the boiler B and with the pipe P, and provided with the check-valve V between the said water-back and boiler, substantially as and for the purpose specified.

- GEO. STEELE. Witnesses:

BENJAMIN W. HOFFMAN, FRED. HAYNES. 

